Low acoustic noise head actuator

DETAILED DESCRIPTION What is claimed is: 1.
A disk drive system for recording and/or reproducing data on a disk in a plurality of substantially circular, concentric tracks, said system comprising: head means for recording and/or reproducing said data in said tracks; actuator means for positioning said head means at a desired one of said tracks; a mechanical mounting structure for mounting at least said actuator means; controller means for generating a selected one of a track access signal and a track jump signal; closed loop servo control means having predetermined operating parameters for controlling said actuator means to respond to said track access signal to perform a track access operation in which said head means is moved across a relatively large number of said tracks to reach said desired track and to respond to said track jump signal to perform a track jump operation in which said head means is moved across a relatively small number of said tracks to reach said desired track; and means for modifying the operating parameters of said servo control means in response to said track jump signal.
2.
A disk drive system according to claim 1; wherein said servo control means exhibits gain and bandwidth and said means for modifying includes means for reducing a gain-bandwidth product of said servo control means in response to said track jump signal.
3.
A disk drive system according to claim 2; wherein said servo control means includes a feed forward input for supplying a feed forward signal to said actuator means and said reducing means includes switch means for removing said feed forward signal from said actuator means in response to said track jump signal.
4.
A disk drive system according to claim 2; wherein said servo control means includes a closed loop, a gain-bandwidth reducing circuit, and switch means for connecting said gain-bandwidth reducing circuit in said closed loop in response to said track jump signal.
5.
A disk drive system according to claim 4; wherein said closed loop includes a parallel combination of a first parallel connection of an operational amplifier and a first resistor and said gain-bandwidth reducing circuit includes a second parallel connection of a capacitor and a second resistor, and said switch means connects said second parallel connection in parallel with said first parallel connection in response to said track jump signal